U.S. Pat. No. 3,647,399 to Ashby and Kobetz describes the first successful synthesis of the alkali metal beryllium tetrahydrides. The process they employed involves the reaction of a beryllium dialkyl, BeR.sub.2 (R=alkyl of 1 to 10 carbon atoms), with a compound of the formula MAlR.sub.3 H, MAlR.sub.2 H.sub.2, or a mixture of both such compounds (M=alkali metal).
A more desirable process for the synthesis of alkali metal beryllium tetrahydrides involves subjecting a mixture of beryllium and an alkali metal aluminum complex of the formula EQU MAlR.sub.m H.sub.n
wherein M is an alkali metal, R is a hydrocarbyl group, m is an integer from 1 to 4, n is an integer from 0 to 3, the total of m and n being 4, to a pressurized atmosphere of hydrogen and an elevated temperature at which alkali metal beryllium tetrahydride of the formula M.sub.2 BeH.sub.4 is produced. Such a process is described in detail in copending application Ser. No. 566,193, filed Dec. 28, 1983 by Roy J. Laran and assigned to the same assignee as the assignee of the present application.